Connectivity Question

[sesha1234]

Please suggest: I have to establish connectivity between two sites. We ahve a IPL Circuit between the two sites. On, site 1, users are on 10.111.0.1 subnet and WAN link is 10.222.0.1. On site 2, WAN link is 10.222.0.2 and LAN is on 192.168.40.0. Please suggest a best way for establishing the connectivity between two sites? I am thinking of NATting internal users at Site1 to the WAN link address and NaTting users from site 2 into Site1. Similarly at Site 2. Is it the right way or is there any other way like adding static routes, etc? Please help. Thank you.

[Kevin Dorrell]

If, I understand you correctly, you can do this very simply with static routes.

On site 1

ip route 192.168.40.0 255.255.255.0 10.222.0.2

On site 2:

ip route 10.111.0.0 255.255.255.0 10.222.0.1

Make sure that the users on each site are set up with their default gateway as the local router, and it should all burst into life.

Kevin Dorrell

Luxembourg

[sesha1234]

Thanks for the reply. Have one more question. How come users on 10.111.0.0 subnet can't ping the serial link on the site 1. (10.222.0.1)? The default gateway on their workstations is set to Fast ethernet (Internal) IP of the router (10.111.0.1)

[Kevin Dorrell]

Is the serial line actually up, and can the routers ping each other using their respective link IP addresses?

Can the users ping 10.111.0.1?

Kevin Dorrell

Luxembourg

[sesha1234]

The users can ping 10.111.0.1. The serial line is UP but line protocol is down for now. I'll connect it again today to the router here at my site. Is that the reason? But the users don't need the WAN link to ping serail interface from inside..is that right?

[Kevin Dorrell]

Well, actually they do. The serial IP address will not respond unless the line protocol is up.

Note that the behaviour is slightly different depending on where you are pinging from. If you ping from an address outside the router, the router itself will respond provided the link is up. But if you ping the router's link IP address from within the router, it will actually send the ping looped back, i.e. it will go out to the other router and back again. That is on a serial link - on an Ethernet link the local interface responds just like a ping from outside the box.

One thing you could try is making a loopback interface on the router. That is always up, whatever you do, and it is a useful confidence check if you can ping it from outside. Has lots of other useful purposes as well.

int lo0

ip address 192.168.42.1 255.255.255.255

Kevin Dorrell

Luxembourg